Ford Mustang/Capri 1979-1988 Repair Guide

Fuel Pressure Regulator


The fuel pressure regulator is attached to the fuel supply manifold assembly downstream of the fuel injectors. It regulates the fuel pressure supplied to the injectors. The regulator is a diaphragm operated relief valve in which one side of the diaphragm senses fuel pressure and the other side is subjected to intake manifold pressure. The nominal fuel pressure is established by a spring preload applied to the diaphragm. Balancing one side of the diaphragm with manifold pressure maintains a constant fuel pressure drop across the injectors. Fuel, in excess of that used by the engine, is bypassed through the regulator and returns to the fuel tank.


Before attempting this procedure, depressurize the fuel system.

  1. Remove the vacuum line at the pressure regulator.
  3. Remove the three Allen retaining screws from the regulator housing.
  5. Remove the pressure regulator, gasket and O-ring. Discard the gasket and inspect the O-ring for deterioration.

If scraping is necessary be careful not to damage the gasket surface.

  1. Installation is the reverse of removal. Lubricate the O-ring with light oil prior to installation. Tighten the three screws 27-40 inch lbs.